Research On The Motion Of Underwater Glider In Vertical Plane

The research is focused on the vertical plane motion of underwater glider. On the base of dynamic equations derived using glider model and hydrodynamic model which includes glider's external configuration parameters, computer program is established to analyze systematically the influence of external configuration on the glider's primary working state: steady glide motion in vertical plane. The present research work provides a simple and efficiency method of performance prediction in preliminary design phase.This research can be divided into four parts: establishment of glider's simplified model in accord with real situation, deriving the motion equations in vertical plane using simplified glider model, conducting out efficiency analysis using motion equations to find out the direction of the following research works; using various engineering estimation methods to establish the hydrodynamic engineering computation model including external configuration parameters, but the basic hydrodynamic data of the glider's parts are computed directly by CFD ; applying the hydrodynamic model into the equilibrium equations of steady glide motion in vertical plane to research systematically on the relation between configuration parameters and steady motion; solving numerically the ordinary difference equations of unsteady motion to discuss on the applicability of the hydrodynamic model in unsteady motion which may include the situation with a great angle of attack and to simulate and analyze glider's unsteady motion characteristics.Due to the similarity between the figuration of underwater glider and airplane's, methods for prediction airplane's aerodynamic characteristics in aircraft design are used extensively in the establishment of hydrodynamic model. Because the Reynolds numbers of underwater glider related problems are much smaller than those of airplane problems, it is necessary to validate the hydrodynamic model's precision. Commercial CFD software Fluent is used to simulate the glider's fluid field. The numerical results of CFD will be compared with estimated results of the hydrodynamic model.Through the validating works of different aspects, it can be concluded that the hydrodynamic engineering computation model have enough efficiency and precision to be applied into the researches of glider's steady motion and unsteady motion.